There is no fastest way to reduce swelling in adult mumps, depending on the cause there may be antiviral, antibiotic or acidic food options to help reduce swelling. Mumps in adults can be caused by bacterial or viral infections, or by poor salivary secretion, and treatments vary depending on the cause. 1. If mumps is caused by a bacterial infection, it needs to be treated with antibiotics, such as cefixime and amoxicillin clavulanate potassium. 2. If the mumps is caused by a viral infection, it is a self-limiting disease and usually only requires appropriate isolation and symptomatic treatment with antiviral medications, such as ribavirin, oseltamivir, etc., and can heal on its own in about 10 to 14 days. 3. If it is caused by poor salivary secretion, you can eat some acidic foods or stimulating foods, which can stimulate salivary secretion and help relieve the symptoms of mumps. Adults with mumps are advised to seek prompt medical attention. Drugs need to be used under the guidance of a professional physician, and should not be used arbitrarily on their own.